Parts with the same mark are managed internally as a group. If the mark of a part is changed, all the other part marks within a group will change. This tool extracts parts from such a group. The part marks are also deleted and you can give a different number.
To access the command
Ribbon: Output > Part Marks: 
Command line: _AstM5equalpartsReset
How to delete the part marks
- Output tab, Part marks panel, switch to the single part or assembly.
- Select the element for which you want to define another park mark, independently of the other parts in the group.
- On the
Output
tab, Part marks panel: Click .
- Click Yes in the warning window.
- The part mark is deleted.